Abstract : The patent application describes an apparatus for and a method of determining the presence and concentration of trace metals in seawater which relies on anodic stripping voltammetry. A tubular mercury-graphite electrode is suitably coupled to receive a flowing mercury plating solution and a thin film of mercury is deposited on the inner surface of the electrode when a plating potential is coupled to the electrode. Next, a seawater sample is pumped through the electrode and trace metals are reduced onto the active mercury film when the plating potential is reconnected to the electrode. At discrete levels within a scanning potential gradient certain ones of the trace metals are stripped from the active metal film and the values of the currents at these levels are monitored and recorded. Zinc, cadmium, lead and copper concentrations are readily observable. The method and apparatus are capable of nearly real-time iteration to enable a more accurate determination of trace metal concentration.